NASA Parts Selection List (NPSL)

Diodes, Silicon
Rectifier
Switching

APPLICATION NOTES:

1)  The 1N4148-1 diode types are NOT recommended for new designs.  These devices (especially the surface mount "UR" designation styles) may be susceptible to thermally induced cracking such as may occur during hand soldering.  The 1N6642 diode types made in accordance with MIL-PRF-19500/578 are the recommended replacement for the 1N4148-1 because of a more robust construction and identical electrical performance characteristics.  

• For surface mount, the 1N6642US diodes are direct electrical replacements for the 1N4148UR-1, but they are physically larger and, therefore, cannot be easily interchanged.
• For through-hole applications, the axial leaded 1N6642 diodes are direct form, fit, function replacements for the axial leaded 1N4148-1 types.

Users are strongly advised to familiarize themselves with the manufacturer's recommended installation practices. Specific emphasis must be placed on process controls that minimize thermally induced stresses. This is particularly important for assembly facilities who intend to use hand soldering techniques to install surface mount devices of any component type.

Refer to NASA GSFC Advisory NA-GSFC-2002-01 for further details.